Conventional methods for constructing and performing operations on multiple wells, within a region, require numerous bores and conduits coupled with associated valve trees, wellheads, and other equipment for injection and/or production from each well, located within the region. The costs of the equipment for the construction, control and operation of these multiple wells can be extremely expensive, which, historically, has prevented development of reserves in the oil and gas industry. In addition, obtaining optimal production from each of these multiple wells can be a problem because each underground formation, has its own unique reservoir characteristics, including pressure, temperature, viscosity, permeability, and other characteristics that generally require specific and differing choke pressures, flow rates, stimulation means, etc. for overall production of wells in the region.
An embodiment of the present invention can include providing a manifold string, with a plurality of conduits forming a plurality of pressure barriers with at least one intermediate passageway or annular space, that can be usable to control pressurized, subterranean, fluid-mixture, flow streams, which can be controlled by the manifold string within passageways through subterranean strata for one or more subterranean wells, that can extend from a single main bore. Important uses of this aspect include, for example, constructing and/or operation of one or more subterranean wells from a single surface location, providing the opportunity for simultaneous well activities and/or common batch activities to be performed on a plurality of wells, without the need to remove established barriers, reposition a rig, and/or to re-establish barriers necessary for well control.
An additional embodiment of the present invention includes one or more manifold crossover apparatus, usable with a manifold string to selectively control an innermost and at least one intermediate concentric or annular passageway. The innermost passageway can be usable for communicating flow-controlling devices for engagement in one or more receptacles of a manifold string to provide, for example, the ability to selectively change controlling mechanisms and/or flow paths of subterranean pressurized fluids.
Another embodiment of the present invention enables fluid separation within a plurality of radial passageways that can communicate through orifices within the innermost passageway, with the radial passageways' diverting walls located within annular or concentric passageways, to direct fluid flow to the innermost passageway. Placing fluid controlling devices through the innermost passageway, for engagement within the manifold string, provides further control of fluid-mixture flow streams between passageways of the manifold crossover and the radially inward or radially outward disposed passageways, including the passageway surrounding the manifold string to, for example, enable the crossover of flow between the innermost and concentric passageways. This crossover of flow enables selective control of the flow in the concentric passageway by use of valves, which can be engaged to the innermost passageway for providing selective pressure control of one or more annular or concentric passageways, while retaining the ability to access wells through the innermost passageway.
In another embodiment of the present invention, conventional flow controlling devices are conveyable through the innermost passageway, for engagement within a receptacle or conduits of a manifold string, to selectively control fluid communication by diverting at least a portion of the fluid-mixture flow streams. An example of this embodiment includes the placement of a fluid motor and fluid pump, usable with gas expansion from an underground storage cavern for driving an impellor to pump and inject water for solution mining, during combined operations. An additional example includes, placement of an orifice piston, which can be usable with coiled tubing for under-balanced drilling.
In a related embodiment, flow control devices engagable within a manifold string, a manifold string receptacle, or a plurality of innermost passageway subterranean valves can be usable with one or more manifold crossovers to selectively control pressurized fluid, which can be communicated through the innermost passageway and/or one or more concentric passageways. The flow control devices can be used, for example, to replace traditionally unreliable annulus safety valves with more reliable tubing retrievable valves or, for example, to repair a failed tubing retrievable safety valve for controlling a concentric passageway of an underground storage, within depleted reservoirs or salt caverns, with an insert safety valve placed through the innermost passageway.
Another embodiment of the present invention enables the ability to divert all or a portion of a fluid-mixture flow stream to a another passageway, that can be disposed radially inward or radially outward for the purposes of carrying out simultaneous well construction, well production and/or well injection operations. The simultaneous well construction and/or well operations enables, for example, one or more under-balanced coiled tubing fish-bone sidetracks of a well to be performed more readily, while producing the well to reduce skin damage in a low permeability reservoir, or can further enable underground storage and solution mining operations to be performed simultaneously, thus removing the conventional requirement for a plurality of rig operations and/or high risk snubbing operations to strip out a dewatering string from a gas storage cavern.
Another embodiment of the present invention provides selective control for placing well construction fluid mixtures of gases, liquids and/or solids within a region of the passageway through subterranean strata, while removing pressurized subterranean fluids from the subterranean strata by over-balancing or under-balancing hydrostatic pressures, for example, during proppant frac stimulations, gravel packs and simultaneous underground storage and solution mining operations.
In still another embodiment, the present invention provides an orifice piston apparatus that can be engagable to a manifold crossover and through which cables or conduits may pass during, for example, under-balanced perforating or drilling operations. Engagement, placement and/or removal of the piston can be assisted by differential pressure applied to the face of the piston during simultaneous well construction, injection operations and/or production operations, including for example, performing a mechanical integrity test using a cable, passed through the orifice piston, to measure a gas liquid interface below the final cemented casing shoe of an underground storage cavern.
Another embodiment of the present invention includes the ability to commingle fluid mixture flow streams and/or to separate selected fluid mixture flow streams with an adapted chamber junction. The fluid flow from exit bore conduits can be commingled through the chamber or directed to intermediate concentric passageways disposed radially inward or outward of the chamber. The bore selector can be usable to communicate fluid and/or fluid control devices through the innermost passageway and chamber junction for selectively controlling one or more wells below a single main bore.
Another embodiment of the present invention provides adapted chamber junctions, usable within a single well passageway with a plurality of flow streams, wherein the innermost passageway of a chamber junction exit bore can be axially aligned with the innermost passageway of the chamber and the conduits axially above. At least one more exit bore conduit can contain a radial passageway that can be usable with a bore selector, fluid diverter, straddle, or other flow control device to fluidly communicate between the innermost passageway and the surrounding passageway, or another concentric intermediate passageway.
Another embodiment of the present invention, includes a reduced length manifold crossover with a plurality of radial passageways for communicating from the innermost passageway to the passageway surrounding the manifold string, or a radially outward concentric passageway using radially disposed small conduits, such that flow through the one or more intermediate concentric passageways effectively travels around and past the rounded shapes of the small conduits. In this embodiment, reduced length conventional flow controlling apparatus can be usable to selectively control flow through orifice connections with the innermost passageway to, for example, provide gradual axial adjustments of solution mining fresh water placement during the salt dissolution and/or storage process.
Embodiments of the present invention include methods for selectively controlling pressures, volumes and temperatures of fluids that can be stored and retrieved from a storage space. Examples of such methods include controlled pressurization of a storage cavern, using water or brine, during gas extraction to reduce or minimize the temperature reduction caused by retrieving compressed stored gas through expansion, thus providing a longer withdrawal period before reaching a minimum operating temperature for associated well equipment.
Other embodiments of the present invention include methods for selectively controlling a substantially water interface during solution mining and/or during re-filling of a cavern, for stored fluid extraction. These selective control methods affect the shape of the cavern walls to, in use, control working storage volumes and solution mining rates for varying storage volume turnovers and natural salt creep rates, usable for simultaneous underground hydrocarbon storage and solution mining operations over a number of years, and/or seasonal storage volume turn-overs.
Embodiments of the present invention can include methods for providing a subterranean brine reservoir with a stored product cushion for selectively controlling working volume and displacement of liquids or compressed gases to and from salt caverns, fluidly associated with brine reservoirs holding subterranean heated brine or generating displacement brine that can be fluidly communicated in u-tube like conduit, pumping and/or compression arrangements between caverns.
In related embodiments, the present invention can provide methods for removing salt gas storage cavern sunk construction cost by displacing conventionally irretrievable cushion gas cavern structural support inventories for preventing salt creep with brine from brine reservoirs during high demand, followed by gas refilling and brine displacement during periods of higher gas availability to, for example, improve the economic viability of constructing large scale salt cavern gas storage facilities, as compared to conventional depleted permeable sandstone reservoir storage.
In other embodiments, the present invention can provide methods usable to selectively access and fluidly communicate between a plurality of specific gravity separated fluids, that can be disposed in caverns and subterranean brine reservoirs connected with u-tube like conduit, pumping and/or compression arrangements engaged with manifold crossovers disposed with the caverns.
Still other embodiments of the present invention can provide methods usable to space salt storage caverns and brine reservoirs for salt pillar support within ocean environments, with pipeline or shipping access and an abundance of water and brine absorption capacity usable, for example, to access stored specific gravity separated liquid products above brine with boats and/or pipelines, while performing u-tube fluid communication with gas storage caverns to, for example, perform storage operations during periods of contrary demand between liquids and gas.
Finally, other embodiments of the present invention provide methods for the use of a fluid buffer for transportation pipelines and/or the selective access to fluids of differing specific gravity for use or disposal, for example, pigging pipelines of water and other fluids into a storage cavern, wherein the fluids are selectively accessed by a manifold crossover with specific gravity cavern separation of stored hydrocarbons from water/brine for environmentally safe ocean discharge.
Periodic catastrophic well failures within the well construction and operations industry continue to demonstrate the need for a plurality of conventional, high-strength, metallic conduit, pressure barriers with intermediate concentric passageways, that can be usable for monitoring annuli pressures that are associated with such pressure barriers, particularly as ever deeper and adverse geological reservoirs are targeted and/or more gas storage is required to meet increasing global hydrocarbon demand.
The practical need for improved methods and apparatus usable to more effectively contain subterranean pressures during well construction and production activities is increased by such activities being performed in the ever deeper and higher pressure subterranean regions, which are targeted for their highly productive rates. In addition, the ever increasing demand for under-balanced operations to reduce reservoir skin damage, or the increased need for large underground gas storage facilities placed under or around urban or environmentally sensitive areas, increase the need for such improved methods and apparatus.
Therefore, a practical need exists for apparatus and methods usable for placing a plurality of tubing-conveyed subterranean valves, to contain well pressures, for an associated plurality of passageways to pressurized subterranean regions. In addition, methods and apparatus usable to replace traditionally unreliable annular safety valves are needed, while retaining access to the innermost passageways of associated strings for measuring, monitoring and maintaining the lower end of a subterranean well, including, for example, engaging replacement insert valves and/or other flow control devices usable to construct passageways and control fluid communication and/or pressures within a well.
With the imminent approach of peak liquid hydrocarbon production worldwide, a need exists for lowering the risks and associated costs of developing remaining hydrocarbons. In particular, improved methods and apparatus for underground hydrocarbon gas storage, usable to replace various areas of liquid hydrocarbon and/or coal consumption, and shorten the timeframe for increased rates of return by, for example, enabling simultaneous construction and operation of underground storage wells with a more cost effective single rig visit and, thus, shortening the timeframe for return on investment while lowering cost by removing the conventional need for subsequent well interventions by large hoisting capacity rigs and/or the conventional need for potentially hazardous and expensive snubbing operations to remove dewatering strings from explosive hydrocarbon gas filled storage caverns.
With the size and productivity of conventional hydrocarbon discoveries decreasing, a need exists for methods and apparatus usable to reduce skin damage in low permeability reservoirs, where conventional methods cause permanent productivity loss.
A need exists for systems and methods for reducing underground cavern construction costs and for retaining innermost bore access, usable for sonar measurements taken from inside and/or outside a leaching string to provide information for better adjusting simultaneous underground storage and solution mining operations. These cost-effective systems and methods must be operable during combined solution mining and storage, especially when encountering unexpected geologic salt deposit features because stored product may prevent large hoisting capacity rig interventions during solution mining conventionally necessary to remove a completion to take a sonar measurement and/or to adjust the depth of the outer leaching string, that controls the depth at which a substantially water interface is placed within a salt dissolution zone.
A need exists for systems and methods for providing improved, cost-effective construction and operation of underground gas storage, particularly within a depleted reservoir sealed by a subterranean cap rock within a dip closure or geologic trapping features, wherein the risk of skin damage to the reservoir's permeability during, or subsequent to, injecting and storing gas results in the need for improved, cost-effective, low skin damage construction and operation. A need exists for systems and methods for providing improved, cost-effective and higher-efficiency permeability retention under-balanced well construction and/or completion operations in, for example, depleted gas storage reservoirs or valved dual conduit completions in gas tight salt cavern reservoirs to, for example, increase working storage volume associated with decreases in required cushion gas volumes required to maintain cavern stability, including the ability to cost-effectively empty a gas storage cavern for seasonal demand requirements.
In analogous well operations, a need exists for valved concentric dual conduit apparatuses and methods usable from a single bore wellhead and valve tree for pressure containment while water flood stimulating of a hydrocarbon reservoir through a single main bore, while producing through the same single main bore for reduced construction cost economic extraction in, for example, instances of insufficient nature economic hydrocarbon flow rate pressures.
With the use of valved dual conduits, a further need exists for storing products in a cushion during simultaneous solution mining and storage operations of brine and storage reservoirs, usable to selectively control working volume and displacement of liquids or compressed gases to and from other salt cavern brine and storage reservoirs, where brine may be subterranean heated and stored or generated during displacement operations through u-tube conduit arrangements between two or more brine and storage reservoirs with fluid pumping and/or compression to, for example, remove the need for cavern stability cushion gas.
With peak hydrocarbon production and the associated changes in consumer demands, a need exists for contra-seasonal storage of gas and liquid hydrocarbons in the same brine and storage reservoir caverns, with selective access to the plurality of specific gravity separated fluids that can be disposed within the reservoirs.
A related economic need exists for reducing salt gas storage cavern sunk construction cost by displacing conventionally irretrievable cushion gas cavern structural support inventories, during high demand periods, with gas refilling and brine displacement during lower demand periods, improving economic viability of larger scale storage facilities.
A related operational need exists for large scale storage facility cavern brine and storage reservoir salt pillar support within an open ocean environment with more flexible fluid communication with pipelines, ships and an abundance of water and brine absorption capacity.
With exploration, transportation and storage of hydrocarbons entering ever more challenging environmentally sensitive and potentially hostile areas, such as the oceans or arctic climates, a need exists for methods and apparatus of smaller foot prints usable to provide a plurality of pressure containing barriers, wherein annuli and passageways between pressure barriers are selectively controllable during well construction and/or well operations, including for example, production during underbalanced perforating and drilling within low permeability reservoirs, production during underbalanced gravel packs within unconsolidated reservoirs, and/or simultaneous gas storage and solution mining for day trading, transportation pipeline buffer storage, and/or pigging in an offshore environment.
Embodiments of the present invention address these needs.